Process for removing solvent from solvent-treated material



M. BONOTTO 2,086,180

PROCESS FOR REMOVING SOLVENT FROM SOLVENT TREATED MATERIAL July 6, 1937.

Filed July 15, 1935 0 Q m a V W 1% Q 7 o W Q J H 8 i v z I. f V Z A, My 6b 2 0 H W1 m i M m 1 Patented July 6, 1937 PROCESS FOR REMOVING SOLVENT FROM SOLVENT-TREATED MATERIAL Michele Bonotto, Evansville, Ind., assignor, by

mesne assignments, to American Soya Products CorporatiomEvans of Indiana ville, Ind., a corporation Application at 15, mistrial at. 31,541"

6 Claims.

This invention relates to processes of removing solvent from materials treated with solvent; and apparatus for use in connection therewith.

In the batch treatment of material such, for

example, as soya beans for the purpose of extracting oil, it has been customary to place the material to be treated in an extractor and to pass solvent, such as gasoline, through the materiai. The solvent is finally conveyed from the extractor to a holder where it may be distilled and separated from the extracted oil.

In order to remove the solvent which remains in the soya bean or other material from which oil has been thus extracted, it has been customary to pass steam through the material for the purpose of carrying off the solvent. If the removal of the solvent is conducted at atmospheric pressure the steam is introduced into the bottom of the extractor and allowed to pass through the mass of material and the admixed steam andsolvent carried thereby are conveyed from the top of the extractor to a condenser. When the removal of solvent is conducted under vacuum,

the mass of material from which the solvent is to be eliminated is usually transferred to a drier where the material is agitated and vacuum ap-' plied for the purpose of eliminating the solvent at low temperature. Such apparatus requires a dust collector to be inserted between the drier and the suction device to prevent small particles from reaching the pumps or condenser through the ejectors.

The methods of removing solvent hereinabove,

mentioned are objectionable in that when steam *1 is applied to the mass of material in the extractor, a drop in temperature, due to quick evaporation of the solvent, takes place and condensation occurs which makes it practically impossible to efilciently remove the solvent.v The condensa- 4 tion of steam causes clogging which makes it very dimcult for the admixed steam and solvent to open its way through the mass of material in the-extractor. It thus becomes necessary to evaporate not only the solvent but also the 5 condensed water. Superheating of the steam to a'high degree does not overcome this difilculty and, furthermore, the use of highly superheated steam is undesirable if coagulation of the protein in the solvent-treated material is to be 50 avoided. While the solvent-treated material may be transferred from the extractor to an agitator and drier device, such apparatus is expensive and theadditional handling of the material increases unduly the length of the operation and the ex- 55 pense thereof.

one side of the top N5 of the extractor.

By the use of my process and apparatus herein described, the need for atmospheric agitator and drier constructions and for vacuum driers with dust collectors and expensive fittings is eliminated. 5

The object of the present invention is to devise a process and apparatus for removing solvent from solvent-treated material by-the use of steam, without removing the material from the extractor in which the oil extraction has taken place and 10 without having such condensation occur as will interfere with the efliciency of the steam for carrying oiI the solvent. I

In the drawing Ihave shown one form of apparatus for use in carrying. out my process, said 15 apparatus comprising an extractor in which material such as soya beans. and the like may be treated with solvent for the purpose of extracting oil from the material,, and in which the solvent-treated material remains until the solvent remaining after extraction has been removed.

Fig. 1 is a vertical sectional view of apparatus embodying my invention, I

Fig. 2 is a horizontal section, on a reduced scale, takenvonthe line 2.2.of Fig. 1, looking downwardly as indicated by. the arrows.

In that embodiment; of the invention'shown in the drawing, l0 indicates acylindrical extractor housing having a conical lower portion VII and conical upper portion I2. A strainer I3 is W secured to an annular flange H at the top of the conical portion l2. Solvent may be introduced or withdrawn through the conduit 15 at A vapor nozzle IT projects from the top l6 and may be connected with a condenser (not shown). At the bottom of the conical portion II is another strainer IS. A conduit l9 enters the bottom 20 of the extractor, and like the conduit l5 p ovides a solvent nozzle through which the solvent may be introduced into or withdrawn from theextractor.

The parts described comprise conventional extractor apparatus. To make such apparatus serve my purpose of removing solvent from .solventtreated material, I provide a steam pipe 2| which carries superheated steam through valves 22 to a plurality of steam conduits in ring form which surround the extractor I0. In the present emforced toward the center of the mass in the tity of solvent to be eliminated.

proximately 4600 poundsot soybean'fiakes'hy 1 equipment: After the"oil' extraction is finished 2t 1s a aisate-cl sed bymeans-"or' aiiy suitable 'will not contain; at the" cornpletio of I the exso solvent, brzaoo oimasr p w 'I havefound that approximately ninety percent'oi the solvent will be'evaporat'edat a 'v"ery"" 2 a aam 1 .twenty overall length, five feet in diameter, through the steam'1ring undei 'ione' c 'at the *riozltl's'il-H penetrate the extractor interior six to ten inches from the extractor wall III. This arrangement permits the steam to be rate of approximately 237 pounds per hour, and when the temperature of the mass reaches the temperature of the steam under the existing condition of the vacuum, all of the solvent will have been evaporated and the mass will be perfectly dry. At that point the steam starting from the. bottomrings is shutofl and. after. breakins {the vacuum, the extractor is iunloadd in any The extractor is thus divided into"superposed suitable manner.

theoretical zones indicated in the drawing at.A, If the evaporation of the solvent takes place B and C. The number of zones and rings'i'l at atmospheric pressure, the same general and the distances between'isaidiringsi carryingfliJthermo-dynamic calculations must be made at nozzles 2l25 depends upon the'iiiida'nd quin-uatmospnenc pressure and instead of connecting vapor -nozzle lfl with a vacuum producing As an example of my inven rshall des c rib'e an extractor and drierapparatus.fapiproxirnateiy ;T with acondenser. The length of the zones must twenty feet in length, five feet in diameter, used be decreased its. solvent is used with higher for the extraction of oil from a charge of apboiling point. If I use a solvent with a boiling range, for-example from 180 to 200 F., instead ory-three zones, as in the case I have already described, I subdivide the extractor i nto four zones assuming; thatthe same a: 'e' oi u heating to be-'f" used as The steam willb intrbd as: in the vacuum process? extractor and prevents collection or condensation of steam inthe nozzles. The nozzles 24 of one ring, maybe staggeredwith, respect to those of an adjacent ringg' means of gasoline, under vacuum.;';;The vapor nozzlel'l is connected with vacuum producing and the" solvent and i031 ithdriawnj the conduits 'valves andtheco'ndenser conduit 'llis'f opened." According to my experimentsthe soy bean fiakes The length of the zones, th at 'lm e an t 1 tance between the stearn'jringl h ing" to the quality or the solvent 1 and a to the degree of superheating traction cycle more than "fi f tyf percent gasoline rapid rate without assistance 'b'y'f'the admission ""oi steam directly to theextractor drierl Only in'- order'to avoidfc onden'sation in thechfafrge of 85 the final ten percent oisolvent tdbe extractedrequires the introduction' oi' steam to accomplish 4Q pounds' perhour,ninety percent-oi the solvent pounds per hour maximumsteam' shouidlbe admittedinto the extractor;

solvent at the rate of about 1920- pounds per hour 5o inorder to remove the remaining solvent esti- 5 5 extractor reaches ajtemperature ofl I80"F., the

* capable oi; maintaining" a vacuum' sufilciently fhigh to pre've'n't condensationfoi "the steam at 65 ring below the zone'A, I j firstintroduce super- Z'Oadrnit't'ed throughthe' steam ring undor the zone "reaches the "temperature'o'f the steam u'nderthe g I Y 7 V i'fiexistingcon ditions oi vacuum. stearn'is admitted steam into;superposedjzonesfoi th,

maintain a yacuumoi' 21.55 inchesot mercury whichicorresporids" to a temperature of 180" F.

" material of the steam and to "maintain the iihaits removala reasonable length of] time. '7 If "'f-the vacuum producing" equipment is "capable of Itfisto be understood that jthe fquairtities of removing the gasoline vapor-attire 'ra'teof 2760 materials; temperatureisfand ,tim I9 t he ar re e b w r will have 'evaporatedinfiorty fiveminutes' and thatfthey may be varied accord the initial temperature of 160 -11 will"haveheen ad capacity of theequi'pr'nent;

r'edu c'ed' 'to' 10 8-'F. 'Wh en'ateinfiraturefof' fwventfthe temperatureioi th'e stea 'is'-reached;"I estimate thatapproximately 475 ohditions' attending' thefextra operations. f, M Itwil1 also be understood h "conditions, I may preierjtof ever j""treatm'ejnt "steam or th "superposed z'ones a's here p v M ,r'j-m'w desireto inject "steamfiritof'th C. "QB" and A in'the' ordenstatedfland*to' cari'y-ofl the-admixed steam and solveiipitmoiignthe bot:

The vacuum producing eq uipmentshould have capacity *to handlefthe steam and th'e'remaining Iclaimq F *1. The process of extracting oilfro byrriz aris,oi'solvent in'an extractor -the extracted material warrant remova I extractor, which comprises njecting into superposed zones of; the solvent-treat terial, said stearn'being firstintroduce'dfin the '1' upperm st zone ia'nd the injectiorifcontinued" untractor as in mepriorart; wil l be introduced til'the temperature of me n atmm has *in"-su'cc'essi-ve stage's b'y-the nozzles corri'rnun'icatraised to ajpr'edeterrriinedpoir 't s1 ing with the steam rings, Through the steam? ingthen injected into the next lowe zen land inflectioncont'inued'in the-' p "zoiie,- iintil starn has been injected Iin'to each ncludvacuum eo'ui'prr'ien't will have established and be 5 that temperature.

* heated steam 'at' the"-rate oi appro'xiniately 70 pounds per hour." Whehtheteniperature in zone mg the lowermost and-the tempe'rat A is eciual to the temp rature theste'am at" zone raised to said i predetermined; the existing condition-of vacuum"steam" will be Pa t a carrying ofi'the admixed steam'land solven from the materia the rate r in'j ect'io'riof tnfl being progressively fgreaterior each ,suece B-at"the rate or approximately '158pouri'ds per I hour, while the'stearn ring under't-he Zo'neA is "st'ill-blowing'.fAfter thetemperature in zone B ive zone" I I "21 The process oiremoving' solvenerp f "vent-treated material, which comprises njecting equipment, the above nozzle is connected directlym: as p ?hi her" han we? tm that is coming from 'the ringbelowea'ch' zo'ne;

the steam injections for the several zones commencing at successive intervals of time, the rate per pound per hour of steam injection being increased for each zone over the previously treated zone, said steam injection being continued in each of the zones until all have been steamtreated, and carrying ofi the admixed steam and solvent from the material.

3. The process of removing solvent from solvent-treated material, which comprises injecting steam into superposed zones of the material, the steam injections for the several zones commencing at successive intervals of time, beginning with the uppermost zone and progressing downwardly, and the rate of injection being progressively greater for each successive zone, continuing said steam injection in each of the zones until the lowermost zone has been sufficiently treated, and carrying off the admixed steam and solvent from the material.

4. The process'of removing solvent from solyent-treated material, which comprises carrying of! part of the solvent under vacuum, injecting steam into superposed zones of the material, the steam injections for the several zones commencing at successive intervals of time, and the rate of injection-being progressively greater for each successive zone, continuing said steam injection in each of the zones until all have been steam treated, andcarrying off the admixed steam and remaining solvent from the material.

5. The process of removing solvent from solvent-treated material without agitating said material, which comprises injecting steam into superposed zones of the material, the steam injections for the several zones commencing at successive times, beginning with the zone nearest the steam and solvent exit and progressing in the order of their location to the zone farthest from said exit, the steam injections continuing in each zone until all have been treated, the rate of injection being progressively greater for each successive zone, and at the end of said treatment carrying 011? the admixed steam and solvent from the material.

6. The process of removing solvent from solvent-treated material without agitating said material, which comprises injecting steam into superposed zones of the material, the steam injections for the several zones commencing at successive times, beginning with the zone nearest the steam and solvent exit and progressing in the order oittheir-location to the zone iarthest from said exit, the steam injections continuing in each zone until all have been treated, the rate of injection being progressively greater for each successive zone, and at the end of said treatment cutting of! the steam in successive zones beginning with the last one treated, and carrying oil the admixed steam and solvent from the material.

MICHELE BONOTTO. 

